Tomograph for the production of transverse layer images
AssigneeSiemens Aktiengesellschaft
InventorFranz Mueller
Life of this patent
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Abstract
In an exemplary embodiment, several measuring channels include amplifier circuits subject to zero point drift during measuring signal interruptions. For each measuring channel of the radiation receiver, a register comprising a plurality of memory locations for correction values is present, whose input is connected to the measuring channel output following the amplifier circuit and whose output is connected to the measuring channel input in front of the amplifier circuit. Each register supplies to the associated measuring channel input a correction signal having a value in dependence upon the measuring channel output signal during a preceding signal interruption and such as to correct for any zero point drift of the amplifier circuit.
Claims3
Tomographic apparatus for the production of transverse layer images of a radiography subject, comprising a radiation measuring arrangement including a radiation source for generating a radiation beam penetrating the radiography subject, whose cross-sectional extent perpendicular to the layer plane is approximately equal to the layer thickness, and a radiation receiver with an array of measuring channels for converting the radiation intensity behind the subject into corresponding electrical signals, comprising a rotating device for the measuring arrangement, and comprising a measured value converter for the transformation of the signals delivered by the radiation receiver into a layer image, each measuring channel of the radiation receiver including an individual detector of the radiation receiver and an amplifier circuit, and having a measuring channel input connected with the individual detector for receiving a measured value signal to be processed, and a measuring channel output connected with the amplifier circuit for supplying measured value output signals during measurement cycles and being operative to supply further output signals during measurement signal interruptions, each measuring channel (I through n) of the radiation receiver (2) having correction value generator means (Ib through nb) with an input connected to the measuring channel output following the amplifier circuit (Ia through na), and having an output connected to the measuring channel input in front of the amplifier circuit (Ia through na), and means comprising said correction value generator means for generating a correction signal which is a function of any deviation of a further output signal at each measuring channel output from a predetermined null output value during a measurement signal interruption, said correction signal generator means being operative for supplying the correction signal so generated to the corresponding measuring channel input during a subsequent measurement cycle for correcting the resulting measured value output signal supplied at the measuring channel output, characterized in that the correction value generator means comprises a register (Ib through nb) with a plurality of memory locations for supplying respective correction values.
Dependencies are inferred from the claim text.